JPH0798198B2 - Granulated sand produced from stonewashing sludge and its granulation method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to granulated sand produced from stone-washing waste mud and a granulating method thereof.

[0002]

2. Description of the Related Art In a crushed stone factory, in the process of manufacturing a product (crushed stone, crushed sand), generally, fine powder is removed with washing water before shipment. In this washing step, washing muddy water containing a large amount of fine particles is generated, and the treatment thereof becomes a big problem in relation to environmental pollution. That is, if the fine particles flow out and accumulate, the respiratory action of the roots of plants is impeded, and in the case of rivers and lakes, it hinders the growth of water algae, which has adverse effects such as the inability of fish to live. Unacceptable. Therefore, when treating turbid water at a crushed stone factory, a flocculating agent and a flocculation sedimentation device are generally used to settle the fine particles, and then forcefully dehydrate until the water content becomes a processable value with a filter press etc. and dispose of as waste mud. ing.

By the way, the amount of the stone washing waste mud generated by the coagulation sedimentation separation device is very large (200 to 300 tons per day even in a medium-sized crushed stone factory), and the characteristics of the stone washing waste mud are soft and viscous. Since it is a soil type, unlike normal residual soil, it does not dry well, and it is difficult to secure a dump site,
When throwing away, it is necessary to add soil and stack it in a sandwich form, so the cost of disposing of waste mud is too high, and the crushed stone collection site is generally not located on a remote site such as a mountain where transportation is carried out during transportation. In addition to the increase in transportation costs, there are pollution problems such as natural destruction and environmental pollution. Conventionally, in general, methods such as backfilling the washed stone sludge into holes excavated at the crushed stone site or using it as landfill as industrial waste have been dealt with. Even if it is covered with a sandwich, it has the above-mentioned properties, and in combination with the effects of rainwater, waste mud does not solidify for a long period of time and remains in an unstable state as it is grubby, and even when it is used as landfill. It had to be constrained. Conventionally, a method for effectively utilizing such stone-washing waste sludge as a civil engineering material or a building material for road subgrade materials, roadbed materials, etc. has not yet been developed and implemented, and the enormous amount of crushed stone plants generated in various places has occurred. The reality is that we are struggling with the disposal of a large amount of stone washing sludge.

As a method for reforming excavated soil that has been conventionally used for reusing or easily discarding excavated soil that has been generated in oil wells, tunnel construction, and other civil engineering constructions (see, for example, Japanese Patent Laid-Open No. 64-51198). ), A natural water-soluble polymer substance, or a semi-synthetic polymer substance thereof, a synthetic water-soluble polymer substance having cohesiveness, or one selected from a water-absorbing resin,
Alternatively, a method of modifying excavated soil has been proposed in which two or more kinds of polymer substances are added to and mixed with excavated soil produced during excavation, and then hydraulic cement is mixed. However, this is simply a powder, and is insufficient in strength as a civil engineering material or building material such as road subgrade materials and roadbed materials such as the present invention, or is powdery. In addition, during its handling, it floats up in the air, or is limited to a specific application depending on the nature and shape of the material. Further, a slurry-like material produced by the conventional neutralization treatment of mine mine wastewater, which is treated by adding and mixing a cement-based solidifying agent (JP-A-1-164499), incineration ash, waste sand, sludge, etc. A method in which a binder is mixed with the waste to form and solidify the waste into granules, and then the entire surface of the solidified waste is coated with a substance having water impermeability and corrosion resistance (Japanese Patent Laid-Open No. Sho 5).
1-108671), it is simply solidified with cement or mixed with a binder to form waste particles.
After solidifying, the entire surface of the solidified waste is impermeable to water.
It is coated with a substance having corrosion resistance, and the property effect is different between the cement solidifying material and the asphalt-based additive material of the present invention. Furthermore, after adding hydraulic cement, a polymer flocculant and bentonite to the dredging waste mud, granules in water (Japanese Patent Publication No. 56-46920), crushed stone washing wastewater, coal washing wastewater, etc. Is added, and the sludge obtained by separating water is further molded with an additional amount of a polymeric flocculant together with or alone as cement, followed by heat treatment to obtain a molded product having water resistance. A process comprising a first step and a second step in which a thermosetting resin liquid is attached to the surface of the molded product and then heat-treated to obtain a high-strength molded product (Japanese Patent Publication No.
No. 37107), but since neither of them is an asphalt-based emulsion as an additive material, it cannot be effectively used as a civil engineering material such as a roadbed material for roads or a roadbed material, or a construction material, and its property effect. However, since these are granulated in water or granulated by heating, the cost is too high, and the polymeric flocculant is expensive.
Furthermore, there are many granulated sludge cakes. However, the solidified product with cement requires a crushing step in order to form a granular material, and a stable particle size cannot be obtained. Furthermore, granulating various sludge cakes is not suitable at all for strength and material as civil engineering materials or building materials.

[0005]

Therefore, as an example of the composition measurement of the stone washing waste mud, the clay (5 um or less) content is about 30.
%, Silt (5-75um) 40%, sand (75um)
Paying attention to the fact that the content of 30 to 2 mm) is 30%, an artificial granulation sand having a strength that can easily and sufficiently use stone washing waste mud as a civil engineering material or a construction material and a granulation method thereof are provided. It is the one we are trying to provide. Furthermore, cement-based solidification
Utilizing reaction heat of wood to increase surface strength and accelerate drying of granulated sand
And to measure .

[0006]

In order to solve the above problems, the present invention firstly comprises adding a cement-based solidifying material to a stone washing waste mud and adding an asphalt-based emulsion to the mixture and mixing them. and the gist granulated sand obtained, the second
In addition to adding cement-based solidifying material to the stone washing waste mud,
Add asphalt emulsion as an additive and mix
The surface of the granulated sand obtained by combining
The main point is granulated sand coated with a powder of resin or resin , and thirdly, a mixture of cement-based as a solidifying material and asphalt-based as an additive is mixed with stone washing waste mud and granulated by a granulator. Fourthly, mixing the cement-based cement as a solidifying agent and the asphalt-based emulsion as an additive into the stone washing waste mud, and after granulating with a granulator, increase the surface strength and accelerate drying. The gist is that a cement-based or resin-based powder is sprayed on the surface of the granulated product as an auxiliary agent for.

[0007]

[Examples] Raw materials: stone washing waste mud, cement-based solidifying material, asphalt-based emulsion as an additive, cement-based or resin-based powder as an auxiliary agent for increasing surface strength and promoting drying. Mixing ratio: 80 to 85% (weight ratio) of stone washing waste mud, 10 to 17% of cement-based solidifying agent, 3 to 10% of asphalt-based emulsion additive, cement-based and resin-based powder auxiliary agent of granulated sand An appropriate amount (a little) according to the production volume. Product status: 6 under normal conditions, depending on the size of the granulator
Granulating sand (hereinafter referred to as stone washed waste mud granules) that was very well mixed was produced by a mixer operation for 75 minutes (capacity: 75 liters). Property test: Granules of stone washed waste mud with a particle size of 2.36 mm or less are no different from natural sand by visual observation or touch, and are used as artificial sand for sand faults and backfilling, as well as for crushed stone with adjusted grain size. Was tested as to whether or not it could be used as a substitute for the above, and further, the strength and the like of civil engineering materials such as roadbeds and roadbeds, and construction materials. The test results are shown in Table 1 (particle size test) and Table 2 (CBR test). In Tables 1 and 2, samples A, B, and C are samples of each of the stone washing waste mud obtained by three granulation experiments, and RC sand is recycled concrete sand. Yes, CB
The R test is a test to measure the bearing capacity of the roadbed or roadbed.
This is a method for easily comparing bearing capacity characteristics such as soil in California, USA. A large number of penetration tests were repeated using a typical crusher run as a standard scale, and the average value, when the penetration amount was 2.5 mm 13
70 kg, 2030 kg for 5.0 mm CBR10
It is defined as 0%, and usually the ratio of the load when the penetrating piston with a diameter of 5 cm penetrates 2.5 mm or 5.0 mm and the standard load (1370 kg or 2030 kg) is expressed as a percentage and compared. . The test piece of the present invention uses a 15 cm mold, 4.5 kg rammer,
Drop height 45 cm, 3 layers 67 times each, and after 4 days of water immersion, a CBR penetration test was performed. Cement-based solid
Asphalt emulsion as an additive
As a property effect of the granulated product (granulated sand) obtained by
Improve the fastening effect (increased adhesion) and prevent the aggregate from breaking.
Stop, waterproofing (reduction of water absorption), flexibility, freezing
Prevention is remarkable, and its manufacturing method (during granulation)
Also improved granulation, improved dispersibility, dust prevention, etc.
It is something.

[Table 1]

[Table 2]

As is clear from the results of the above property test, the stone washed waste mud granules (granulated sand) produced by the method of the present invention have excellent characteristics in terms of particle size and strength, and Since the particle size can be arbitrarily selected to some extent, it can be sufficiently used as an artificial sand or gravel as a civil engineering material or a building material for road subgrade materials, roadbed materials, etc. The product (granulated sand) itself can be used as a barrier layer sand, a backfilling sand, and the like.

Immediately after granulating the stone washing waste mud as described above, the stone washing waste mud granules are relatively soft, and the stone washing waste mud granules themselves are generated by the reaction heat of the cement-based solidifying material. Since it is in a state of heat generation, and if it is left as it is, it may aggregate in a dumpling shape.Therefore, as a step after the granulation step, the steps of sizing, drying and curing are added to cure the stone washed waste mud granules. It may be accelerated, and after that, a classification step may be added to classify the stone washed waste mud granules into each predetermined particle size (for example, sorting into several kinds of sand with different particle sizes, (Refer to 1) Flow chart for granulation of stone washed waste mud). By the way, after the granulation process, before the sizing / drying / curing process, the cement-based or resin-based (water-absorbing resin) powder is sprinkled on the surface of the granulated product to obtain the surface strength of the granulated product. And the drying efficiency can be increased. Since the stone washed waste mud granules immediately after granulation generate heat as described above, the drying treatment may be room temperature drying or cold air drying with a normal blower, not fuel drying, and therefore the fuel cost is low. There is an advantage that the work environment is kept good as well as it does not take. In FIG. 1, 1
Is a raw material silo, 2 is a cement silo, 3 is a meter, 4 is an additive tank, 5 is a metering pump, 6 is a granulator, 7 is a metering device, 8 is a powder additive tank 8a and a meter 8b and Powder additive spraying device consisting of sprayer 8c, 9 particle size controlling / drying / curing device, 10 classifying device, 11 blower, 12-
Reference numeral 17 is a conveying device including a belt conveyor, 18 is an oversized storage container, and 19 is a stone washed waste mud granule (product) after classification.

Although the above examples have been described with respect to the stone washing waste mud, that is, the one containing water, the present invention also relates to the dry type stone washing waste mud (in the powder state containing almost no water). By adding a certain amount of water,
It can be used as a similar material. Therefore, in the present invention, the term "stone washing waste mud" is a broad concept including not only wet type waste mud but also dry type stone washing waste mud to which desired water is added.

[0011]

EFFECTS OF THE INVENTION According to the first aspect of the present invention, the troublesome stone-washing sludge that is produced in large quantities in a quarry is utilized to improve the fastening effect (increase in adhesive force) and bone. Material
Prevention, waterproofing (reduction of water absorption), flexibility,
Antifreeze etc. remarkable road for subgrade material, civil engineering material or building material roadbed material or the like or the like is obtained, and sufficient strength and stable granulated sand can withstand use withstand sufficiently the granularity (washing stone It is also a waste sludge, and it is not only possible to solve various problems such as difficulty of securing a dump site when disposing of stone washing waste mud, transportation cost increase and environmental pollution all at once, but also stone washing waste Since mud can be effectively used as artificial sand and artificial gravel, the amount of natural sand etc. that is decreasing year by year can be suppressed as much as possible,
Therefore, it is possible to suppress the destruction of the natural environment such as rivers, coasts, mountains and hills, and it is useful as a new resource. According to the second invention of the present invention, in addition to the effect of the first invention, since the surface of the granulated sand (washed stone waste sludge) is coated with cement-based or resin-based powder, It became more stable and stable enough to withstand more than sufficient strength, particle size that can withstand use.

According to the third aspect of the present invention, the granulating sand obtained by the method for granulating the stone-washing waste mud not only exhibits the above-mentioned effects, but also uses an existing granulator. using, improved granulation, to improve the dispersibility, because the dust prevention, etc. can be obtained a stable granulated sand salient substantially spherical, the production cost does not take much, and safe and hygienic It has an unprecedented useful effect such as being easily manufactured under a typical work environment.

According to the fourth aspect of the present invention, the third aspect
In addition to the effect of heat of reaction of cement-based solidifying material and powder of resin-based
By using cement powder or resin powder as an auxiliary agent on the surface of the granulated sand by using the water absorbency of the powder, it is possible to prevent the granulated sand from sticking together (aggregating) in a dumpling shape. ,
It was possible to obtain a more stable and substantially spherical granulated sand, and to accelerate the drying and enhance the surface strength.

[Brief description of drawings]

FIG. 1 is a flow sheet showing a granulation process, a sizing / drying / curing process, and a classification process of a stone washing waste mud.

[Explanation of symbols]

 1 Raw material silo 2 Cement silo 3 Metering device 4 Additive material tank 5 Metering pump 6 Granulator 7 Quantitative slicing device 8 Powder additive spraying device 8a Powder additive tank 8b Metering device 8c Sprayer 9 Sizing / drying / curing device 10 Classification device 11 Blower 12-17 Conveyor device consisting of belt conveyor 18 Oversize storage container 19 Stone washed waste mud granules (product) after classification treatment

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Someya Inventor Koichi Someya 35 Arakawa, Hanazono-cho, Saitama Prefecture Daiichi Seki Transport Co., Ltd. (56) References JP-A 51-108671 (JP, A) JP 56-46920 (JP, B2) JP-B-49-37107 (JP, B2)

Claims (4)

[Claims] 1. A granulated sand obtained by adding a cement-based solidifying material to a stone washing waste mud and adding an asphalt-based emulsion as an additional material and mixing. 2. When a cement-based solidifying material is added to the stone washing waste mud
Both use asphalt emulsion as an additive
In addition, the surface of the granulated sand obtained by mixing is used as an auxiliary agent.
Granulated sand covered with cement-based or resin-based powder . 3. A stone-based waste mud containing cement as a solidifying material,
A method for granulating stone-washing waste mud, which comprises mixing an asphalt-based emulsion as an additive and granulating with a granulator. 4. A stone-based waste mud containing cement as a solidifying material,
After mixing an asphalt emulsion as an additive and granulating with a granulator, spraying cement-based or resin-based powder on the surface of the granulated sand as an auxiliary agent for increasing surface strength and promoting drying. A method for granulating the stone washing waste mud, which is characterized by